Pyroxylin sheet material



Jan. 30, E. ALUNG 1,945,250

PYROXYLI N SHEET MATERIAL Filed Aug. 20, 1932 Invenibr; 5 villi/Q9, W W

Patented Jan. 30, 1934 PATENT GFFICE PYROXYLIN SHEET MATERIAL Guy E.Ailing, Athol, Mass, assignor to Athol Manufacturing Company, Athol,Mass, a corporation of Massachusetts Application August 20, 1932. SerialNo. 629,658

'7 Claims.

My invention relates to pyroxylin sheet material or web stock useful asa substitute for leather and other purposes as, for example, as acovering for wood heels of shoes and other irregular surfaces for whichleather, celluloid, and fabric materials heretofore have been employed,the invention further relating to methods of making such material.

The pyroxylin sheet material, according to the invention, preferably hascompounded therewith filler and color, and is treated to make itflaccid, as distinguished from sheet celluloid which is merely flexible,the degree of fiaccidity, if desired, and preferably, being such thatthe material may be crumpled without fracture similarly to soft leatheror cloth. This material is further characterized in that, when treatedwith suitable mulling reagents, it may be stretched in all directions,permitting it to be applied to an irregular surface such as the lateralwalls of a wood heel of a shoe. The material is further distinguishedfrom celluloid in that it may be produced in indefinitely long lengthsof Web stock, whereas celluloid may be produced only in relatively smallsheets limited to the dimension of the block of this material from whichthe sheets are sliced. It is not necessary to polish the material aswith celluloid, and further it is closer in appearance to leather thanthis latter material, and may be grained more satisfactorily to imitatethe grain of leather by an embossing process. As compared with leatherit will not scuff, and as compared with textile base materials finishedto represent leather it will not ravel, and, as it stretches whenmulled, it may be applied to an irregular surface without wrinkling.

The above described material will perhaps be best understood from thefollowing description when read in the light of the accompanying drawingof one example of apparatus for practising one method of making one formof the material. 1

In the drawing:-

45 Fig. 1 is a schematic elevation of one form of apparatus for use inconnection with the practice of one process of making pyroxylin webstock;

Fig. 2 is a diagram representing a step in the stripping operation; and

Fig. 3 is a schematic elevation of one form of apparatus for completingthe stripping operation.

Referring to the drawing, the sheet material above described may beformed by coating 2. sur- 551 face, such as the upper surface of a web1, with pyroxylin compound, and, after the coating isdried, stripping itfrom said web.

As an example of a suitable pyroxylin compound for use with thisapparatus, but without limitation thereto, the same may consist of ni-'5,. trated cotton, nitrated wood fiber, or other 111- trated cellulosematerial, dissolved in a suitable substance such as ethyl acetate,benzol, or ethyl alcohol, the solution containing a suitableplasticizer, preferably castor oil, or, if desired, other plasticizerssuch as di-butyl phthalate or similar suitable substances, rape-seed oilor other suit: able vegetable oils, suitable so-called processed oils,and the like, and also suitable filler and color.

As an example of the solvent, but without limita- 70 tion thereto, amixture consisting of 30% ethyl. acetate, benzol, and 20% ethyl alcoholhas been found satisfactory. As a satisfactory exam ple of the compound,but without limitation thereto, I may take 10 to 30 lbs. nitrated cotton75 dissolved in to lbs. of the above mentioned solvent and mix it in achurn with 12 to 14 lbs. castor oil and 6 to '7 lbs. filler containingthe desired amount of coloring pigment, the filler being of the kindcommonly employed in the arts as, for example, whiting, barium sulphate,etc.

The combination of ethyl alcohol and ethyl acetate is preferablyemployed because together they make a better solvent than either usedalone, whfle benzol is preferably employed to serve as a diluent for thesolvent. In general the proportions of the particular example of solventmentioned may be varied from 15% to 40% ethyl acetate, 50% to 26%benzol, and 35% to 40% ethyl alcohol. It will be understood however thatother pyroxylin solvents such as amyl acetate, acetone, methyl acetone,and other homologs of amyl or ethyl acetate or mixtures thereof may eemployed as a solvent, although solvents hav-- ing an ethyl alcohol basefor economic reasons appear to be most satisfactory.

The flaccidity of the pyroxylin sheet or web may be controlled byvarying the amount of plasticizer. For example] if a somewhat stiffproduct is required the castor oil in the above example may be as low as3 lbs., or if extreme limp-.. nose or iiaccidity is desired may be ashigh as 24 lbs.

Conveniently the web 1, upon which the pyroxylin web or sheet is formed,consists of paper or textile material, preferablythe latter, treated toprevent the pyroxylin layer from adhering firmly to it. For this purposethe web maybe rubberized or may be sized with clay filler, glue, casein,starch, or a phenolic condensation prodsil uct (bakelite). The web 1preferably is of such weave or structure that after treatment it issomewhat porous to facilitate the drying of the web or sheet ofpyroxylin.

In one manner of practising the invention, a suitable length of thetreated textile web 1 say, for example, a web 100 yds. in length, may beinitially Wound to form a roll 3 and then be fed from said roll througha drier 5 and wound to form a roll 7. As the web moves from one roll tothe other, the pyroxylin compound may be fed by gravity through thedischarge pipe 9 of a tank 11 containing the compound to form a mass 13of the compound on the upper side of the web behind a doctor knife 15,which latter operates upon the moving Web and compound to spread thelatter over the web in a thin layer. This layer, in the form ofapparatus shown, is dried by the passage of the web 1 through the drier.

After the web 1 has been completely run off the roll 3 to form the roll'7',the latter may be moved to the position shown by the roll 3 in Fig.1, and the operation repeated to apply subsequent coatings of thepyroxylin, as many coatings being applied in this way as necessary tosecure a layer of the desired thickness, and commonly the desiredthickness will be secured with from 2 to 20 coatings. rrereramy, thefinal coatings are so compounded in respect to the color of thematerial', 'or absence of the same, as to give the finish'ed materialthe degree of gloss or dullness desired. 1, v

After the webl has been coated with the pyroxylin to the desiredthickness, the resulting pyroxylin layer may be stripped therefrom.Conveniently, this may be done by making a cut through th'el'ayer on thelines A and B of Fig. 2, which enables the portion of the layer boundedby said lines to be lifted or stripped from the web 1. The' roll '7 ofthe coated web may then be mounted as shown in Fig. 3, and be fed fromthis roll to form a roll 1'7, the stripped end of the coatin'g" beingled to a reel 19 which is rotated continuously to strip'a web or sheet21 of the coating and wind it into a roll 23. Preferably, to facilitatethe stripping operation, the layer of pyroxylin on the web 1 is actedupon by suitable scoring tools, conveniently in the form of scoringrolls 25 which cooperate with platen rolls 27 to form scored lines, atopposite sides of the coating, which are prolongations of the lines B ofFig. 2. The stripped textile sheet 1 may then be recoated for forming asecond pyroxylin sheet 21 in the manner just described.

As has been hereinbefore mentioned, when the pyroxylin sheet materialabove described is to be applied to an irregular surface, such as to thelateral wallsof a Wood heel, it is first mulled, that is to saysoftened, by treating it with a suitable reagent. When mulled thematerial may be stretched in all directions permitting it to be appliedWithout stretching. As suitable examples o'f'mulling reagents I mayemploy water dilutions of'methyl alcohol or acetone, or water dilutionsof other pyroxylin solvents. Dilute methyl alcohol however is preferablyemployed because it has the property of slightly swelling the materialwhen it softens it, allowing the material to be slightly stretchedwithout attenuation.

' When the material is to be embossed, say to grainit in imitation ofcertain leathers, the same may be done in the common manner by use ofembossing rolls or an embossing press, best results ordinarily beingsecured when the rolls or press elements acting on the material aremaintained at about 240 F.

It will be understood that wide deviations may be made from the abovedescribed process, apparatus, and materials Without departing from thespirit of the invention.

I claim:

1. The process of making material useful as a leather substitute and forother purposes which comprises spreading a layer of pyroxylin solutioncontaining a plasticizer upon a substantially air pervious sheet towhich it will not firmly adhere, drying the layer, and stripping thedried layer from said sheet.

2. The process of making material useful as a leather substitute and forother purposes which comprises spreading a layer of pyroxylin solutioncontaining a plasticizer upon a substantially air pervious rubberizedtextile sheet, drying the layer, and stripping the dried layer from saidsheet.

3. The process of making web stock in long lengths useful as a leathersubstitute and for other purposes which comprises spreadinga layer ofpyroxyli-n compound containing a pyroxylin solvent, filler, color, andcastor oil upon a moving substantially air pervious rubberized textileweb, passing the coated web through adrier,- and stripping the coatingfrom said web.

4. The process of making web stock m long lengths useful as a leathersubstitute and for other purposes which comprises spreading apluralityof superimposed coatings of pyroxylin compound containing a solution ofnitrated cotton mixed with filler, color, and castor oil upon amovingsubstantially air pervious rubberized textile web, passing the latterthrough a drier for drying each coating prior to the application of thenext coating, and finally stripping the resulting layer from said web.

5. Flaccid sheets of nitrocellulose compound useful for covering woodheels and other articles containing 10 to 30 pounds nitrated cotton orthe like and 3 to 24 pounds castor oil or equivalent amount of otherpl-asticizer, capable of being mulled to shape them to the heel or otherarticle surface, and characterized by withstanding, without rupture orchecking, warping and cracking of the wood heel or other article body towhich they are applied.

6. Flaccid sheets of nitrocellulose compound useful for covering woodheels and other articles containing 10 to 30 pounds nitrated cotton orthe like and 12 to 14 pounds oastor oil or equivalent amount of otherplasticizer, capable of being mulled to shape them to the heel or otherarticle surface, and characterized by withstanding, without rupture orchecking, warping and cracking of the wood heel or other article body towhich they are applied.

7. Flaccid sheets of nitrocellulose compound useful for covering woodheels and other articles containing 10 to 30 pounds nitrated cotton orthe like, 6 to 7 pounds filler, and 12 to 14 pounds castor oil orequivalent-amount of other plasticiz-' er, capable of being mulled toshape them to the heel or other article surface, and characterized bywithstanding, without rupture orchecking, warping and cracking of thewood heel or" other article body to which they are applied.

E. ALLING'.

